Bad Ground....but, where? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**1971Stepside** · 03-17-2021, 09:37 AM

I have a common problem I believe but didn't have time to fully investigate it last night. Hoping you guys can save me a lot of time.

American Auto Wire harness on a 71 C10. Everything is new in the way of lights and wires. Turn signals work without headlights on as they should. When I turn on headlights the side markers will still flash but the bumper lights will not. It appears to be a ground issue just not sure where.

One thing I did find is that I can twist the wires on the backside of the parking lights and if I get them in just the right position the turn signal works. Could both of the lights be bad (LMC specials)?

I did take one of the lights off the bumper and the low side continued to flash and the high side went dead when it lost its ground to the bumper.

Looking for ideas on where to begin to find the issue. Thanks in advance.

03-17-2021, 09:37 AM	#1
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Bad Ground....but, where? I have a common problem I believe but didn't have time to fully investigate it last night. Hoping you guys can save me a lot of time. American Auto Wire harness on a 71 C10. Everything is new in the way of lights and wires. Turn signals work without headlights on as they should. When I turn on headlights the side markers will still flash but the bumper lights will not. It appears to be a ground issue just not sure where. One thing I did find is that I can twist the wires on the backside of the parking lights and if I get them in just the right position the turn signal works. Could both of the lights be bad (LMC specials)? I did take one of the lights off the bumper and the low side continued to flash and the high side went dead when it lost its ground to the bumper. Looking for ideas on where to begin to find the issue. Thanks in advance. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."



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